Location of Ground Rods for a Sub-Panel in a Detached Garage

[JoeDunn]

Hi Everyone!

I'm new here and my question is:

When installing 2-5/8"x8' ground rods for a detached garage Sub-Panel ... The rods will be driven in to the ground 6" below grade and spaced 8' on center. Assuming that the roof has a 12' overhang with a gutter system draining to the rear of the garage and the rods will be install on the same side as the gutter system ... where in relation to the side of the garage/roof overhang should the rods be installed?

One co-worker says it should set beyond the roof overhand where the grade is slightly higher and less water pools(dry soil provides better grounding). The other persons states it should approx 6"-8" from the garage and under the overhang where the water pools slightly(wet soil provides better grounding).

Also, would it be ok to attached the single ground conductor (#8AWG) from the ground rods to the outside of the Schedule 80 PVC using plastic ties(this conduit runs back to the Main Panel at the house and has 4-#6's H-H-N-G) that runs up the side of the gargae to the Sub-Panel?

Thanks for your input!

Joe

 

[Smart $]

Hi Everyone!

I'm new here and my question is:

When installing 2-5/8"x8' ground rods for a detached garage Sub-Panel ... The rods will be driven in to the ground 6" below grade and spaced 8' on center. Assuming that the roof has a 12' overhang with a gutter system draining to the rear of the garage and the rods will be install on the same side as the gutter system ... where in relation to the side of the garage/roof overhang should the rods be installed?

One co-worker says it should set beyond the roof overhand where the grade is slightly higher and less water pools(dry soil provides better grounding). The other persons states it should approx 6"-8" from the garage and under the overhang where the water pools slightly(wet soil provides better grounding).

Also, would it be ok to attached the single ground conductor (#8AWG) from the ground rods to the outside of the Schedule 80 PVC using plastic ties(this conduit runs back to the Main Panel at the house and has 4-#6's H-H-N-G) that runs up the side of the gargae to the Sub-Panel?

Thanks for your input!

Joe

Welcome :thumbsup:

Wetter earth has better conductivity... rod placement, other than not closer than 6', is strictly a design decision.

Grounding electrode conductors smaller than #6 must be protected by conduit or cable armor [250.64(B)].

 

[ActionDave]

Smart $ gave a very good answer to your question and I will only add that if you are able to pick the location of where you drive a ground rod based on the eave of the house alone you are very lucky.

Where I live you decide where to pound your ground rods by trying one, two, three.....eight, nine, ten....fourteen...twenty-three locations.... until you don't hit a rock. When you finally locate a spot where it goes down eight feet that is where it goes. Now on to the second one.

Thank heaven and all that is good and right for the CEE requirement.

 

[JoeDunn]

Thanks All!

Thanks All!

Welcome :thumbsup:

Wetter earth has better conductivity... rod placement, other than not closer than 6', is strictly a design decision.

Grounding electrode conductors smaller than #6 must be protected by conduit or cable armor [250.64(B)].

The grounding electrode conductor is #6. I made a typo in stating #8. That being said, once my GEC comes out of the ground I'll be along side my Schedule 80 PVC conduit which is feeding my Sub-Panel ... should I attach the GEC to the Schld 80 with plastic ties or install a sleeve just above the slab and in the wall. The sub-panel in question is mounted in that 2x4 chase cavity.

Thanks!

 

[kwired]

The grounding electrode conductor is #6. I made a typo in stating #8. That being said, once my GEC comes out of the ground I'll be along side my Schedule 80 PVC conduit which is feeding my Sub-Panel ... should I attach the GEC to the Schld 80 with plastic ties or install a sleeve just above the slab and in the wall. The sub-panel in question is mounted in that 2x4 chase cavity.

Thanks!

Either method is code compliant.